1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2021 Facebook */
3 #define _GNU_SOURCE
4 #include <sched.h>
5 #include <test_progs.h>
6 #include "network_helpers.h"
7 #include "bpf_dctcp.skel.h"
8 #include "bpf_cubic.skel.h"
9 #include "bpf_iter_setsockopt.skel.h"
10 
create_netns(void)11 static int create_netns(void)
12 {
13 	if (!ASSERT_OK(unshare(CLONE_NEWNET), "create netns"))
14 		return -1;
15 
16 	if (!ASSERT_OK(system("ip link set dev lo up"), "bring up lo"))
17 		return -1;
18 
19 	return 0;
20 }
21 
set_bpf_cubic(int * fds,unsigned int nr_fds)22 static unsigned int set_bpf_cubic(int *fds, unsigned int nr_fds)
23 {
24 	unsigned int i;
25 
26 	for (i = 0; i < nr_fds; i++) {
27 		if (setsockopt(fds[i], SOL_TCP, TCP_CONGESTION, "bpf_cubic",
28 			       sizeof("bpf_cubic")))
29 			return i;
30 	}
31 
32 	return nr_fds;
33 }
34 
check_bpf_dctcp(int * fds,unsigned int nr_fds)35 static unsigned int check_bpf_dctcp(int *fds, unsigned int nr_fds)
36 {
37 	char tcp_cc[16];
38 	socklen_t optlen = sizeof(tcp_cc);
39 	unsigned int i;
40 
41 	for (i = 0; i < nr_fds; i++) {
42 		if (getsockopt(fds[i], SOL_TCP, TCP_CONGESTION,
43 			       tcp_cc, &optlen) ||
44 		    strcmp(tcp_cc, "bpf_dctcp"))
45 			return i;
46 	}
47 
48 	return nr_fds;
49 }
50 
make_established(int listen_fd,unsigned int nr_est,int ** paccepted_fds)51 static int *make_established(int listen_fd, unsigned int nr_est,
52 			     int **paccepted_fds)
53 {
54 	int *est_fds, *accepted_fds;
55 	unsigned int i;
56 
57 	est_fds = malloc(sizeof(*est_fds) * nr_est);
58 	if (!est_fds)
59 		return NULL;
60 
61 	accepted_fds = malloc(sizeof(*accepted_fds) * nr_est);
62 	if (!accepted_fds) {
63 		free(est_fds);
64 		return NULL;
65 	}
66 
67 	for (i = 0; i < nr_est; i++) {
68 		est_fds[i] = connect_to_fd(listen_fd, 0);
69 		if (est_fds[i] == -1)
70 			break;
71 		if (set_bpf_cubic(&est_fds[i], 1) != 1) {
72 			close(est_fds[i]);
73 			break;
74 		}
75 
76 		accepted_fds[i] = accept(listen_fd, NULL, 0);
77 		if (accepted_fds[i] == -1) {
78 			close(est_fds[i]);
79 			break;
80 		}
81 	}
82 
83 	if (!ASSERT_EQ(i, nr_est, "create established fds")) {
84 		free_fds(accepted_fds, i);
85 		free_fds(est_fds, i);
86 		return NULL;
87 	}
88 
89 	*paccepted_fds = accepted_fds;
90 	return est_fds;
91 }
92 
get_local_port(int fd)93 static unsigned short get_local_port(int fd)
94 {
95 	struct sockaddr_in6 addr;
96 	socklen_t addrlen = sizeof(addr);
97 
98 	if (!getsockname(fd, (struct sockaddr *)&addr, &addrlen))
99 		return ntohs(addr.sin6_port);
100 
101 	return 0;
102 }
103 
do_bpf_iter_setsockopt(struct bpf_iter_setsockopt * iter_skel,bool random_retry)104 static void do_bpf_iter_setsockopt(struct bpf_iter_setsockopt *iter_skel,
105 				   bool random_retry)
106 {
107 	int *reuse_listen_fds = NULL, *accepted_fds = NULL, *est_fds = NULL;
108 	unsigned int nr_reuse_listens = 256, nr_est = 256;
109 	int err, iter_fd = -1, listen_fd = -1;
110 	char buf;
111 
112 	/* Prepare non-reuseport listen_fd */
113 	listen_fd = start_server(AF_INET6, SOCK_STREAM, "::1", 0, 0);
114 	if (!ASSERT_GE(listen_fd, 0, "start_server"))
115 		return;
116 	if (!ASSERT_EQ(set_bpf_cubic(&listen_fd, 1), 1,
117 		       "set listen_fd to cubic"))
118 		goto done;
119 	iter_skel->bss->listen_hport = get_local_port(listen_fd);
120 	if (!ASSERT_NEQ(iter_skel->bss->listen_hport, 0,
121 			"get_local_port(listen_fd)"))
122 		goto done;
123 
124 	/* Connect to non-reuseport listen_fd */
125 	est_fds = make_established(listen_fd, nr_est, &accepted_fds);
126 	if (!ASSERT_OK_PTR(est_fds, "create established"))
127 		goto done;
128 
129 	/* Prepare reuseport listen fds */
130 	reuse_listen_fds = start_reuseport_server(AF_INET6, SOCK_STREAM,
131 						  "::1", 0, 0,
132 						  nr_reuse_listens);
133 	if (!ASSERT_OK_PTR(reuse_listen_fds, "start_reuseport_server"))
134 		goto done;
135 	if (!ASSERT_EQ(set_bpf_cubic(reuse_listen_fds, nr_reuse_listens),
136 		       nr_reuse_listens, "set reuse_listen_fds to cubic"))
137 		goto done;
138 	iter_skel->bss->reuse_listen_hport = get_local_port(reuse_listen_fds[0]);
139 	if (!ASSERT_NEQ(iter_skel->bss->reuse_listen_hport, 0,
140 			"get_local_port(reuse_listen_fds[0])"))
141 		goto done;
142 
143 	/* Run bpf tcp iter to switch from bpf_cubic to bpf_dctcp */
144 	iter_skel->bss->random_retry = random_retry;
145 	iter_fd = bpf_iter_create(bpf_link__fd(iter_skel->links.change_tcp_cc));
146 	if (!ASSERT_GE(iter_fd, 0, "create iter_fd"))
147 		goto done;
148 
149 	while ((err = read(iter_fd, &buf, sizeof(buf))) == -1 &&
150 	       errno == EAGAIN)
151 		;
152 	if (!ASSERT_OK(err, "read iter error"))
153 		goto done;
154 
155 	/* Check reuseport listen fds for dctcp */
156 	ASSERT_EQ(check_bpf_dctcp(reuse_listen_fds, nr_reuse_listens),
157 		  nr_reuse_listens,
158 		  "check reuse_listen_fds dctcp");
159 
160 	/* Check non reuseport listen fd for dctcp */
161 	ASSERT_EQ(check_bpf_dctcp(&listen_fd, 1), 1,
162 		  "check listen_fd dctcp");
163 
164 	/* Check established fds for dctcp */
165 	ASSERT_EQ(check_bpf_dctcp(est_fds, nr_est), nr_est,
166 		  "check est_fds dctcp");
167 
168 	/* Check accepted fds for dctcp */
169 	ASSERT_EQ(check_bpf_dctcp(accepted_fds, nr_est), nr_est,
170 		  "check accepted_fds dctcp");
171 
172 done:
173 	if (iter_fd != -1)
174 		close(iter_fd);
175 	if (listen_fd != -1)
176 		close(listen_fd);
177 	free_fds(reuse_listen_fds, nr_reuse_listens);
178 	free_fds(accepted_fds, nr_est);
179 	free_fds(est_fds, nr_est);
180 }
181 
serial_test_bpf_iter_setsockopt(void)182 void serial_test_bpf_iter_setsockopt(void)
183 {
184 	struct bpf_iter_setsockopt *iter_skel = NULL;
185 	struct bpf_cubic *cubic_skel = NULL;
186 	struct bpf_dctcp *dctcp_skel = NULL;
187 	struct bpf_link *cubic_link = NULL;
188 	struct bpf_link *dctcp_link = NULL;
189 
190 	if (create_netns())
191 		return;
192 
193 	/* Load iter_skel */
194 	iter_skel = bpf_iter_setsockopt__open_and_load();
195 	if (!ASSERT_OK_PTR(iter_skel, "iter_skel"))
196 		return;
197 	iter_skel->links.change_tcp_cc = bpf_program__attach_iter(iter_skel->progs.change_tcp_cc, NULL);
198 	if (!ASSERT_OK_PTR(iter_skel->links.change_tcp_cc, "attach iter"))
199 		goto done;
200 
201 	/* Load bpf_cubic */
202 	cubic_skel = bpf_cubic__open_and_load();
203 	if (!ASSERT_OK_PTR(cubic_skel, "cubic_skel"))
204 		goto done;
205 	cubic_link = bpf_map__attach_struct_ops(cubic_skel->maps.cubic);
206 	if (!ASSERT_OK_PTR(cubic_link, "cubic_link"))
207 		goto done;
208 
209 	/* Load bpf_dctcp */
210 	dctcp_skel = bpf_dctcp__open_and_load();
211 	if (!ASSERT_OK_PTR(dctcp_skel, "dctcp_skel"))
212 		goto done;
213 	dctcp_link = bpf_map__attach_struct_ops(dctcp_skel->maps.dctcp);
214 	if (!ASSERT_OK_PTR(dctcp_link, "dctcp_link"))
215 		goto done;
216 
217 	do_bpf_iter_setsockopt(iter_skel, true);
218 	do_bpf_iter_setsockopt(iter_skel, false);
219 
220 done:
221 	bpf_link__destroy(cubic_link);
222 	bpf_link__destroy(dctcp_link);
223 	bpf_cubic__destroy(cubic_skel);
224 	bpf_dctcp__destroy(dctcp_skel);
225 	bpf_iter_setsockopt__destroy(iter_skel);
226 }
227